BCL9 and ductal breast carcinoma in situ: BCL9 KD reduced invasion of DCIS.COM cells (0.23 ± 0.03 fold, p <0.05) compared to control (0.81 ± 0.07), and in SUM225 cells (0.62 ± 0.04 fold, p <0.05) compared to control (1.06 ± 0.05).